Paper making machine



Sept. 4, 1934. w. .1. OBRIEN PAPER MAKING MACHINE Filed Nov. 1931 IMNPatented Sept. 4, 1934 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to paper makingv machines in which the paper ispassed around one or more rotary steam-heated drying cylinders andrefers more particularly to apparatus for automatically controlling thesupply of steam to the cylinders and thereby to regulate the moisturecontent of the paper.

It is, of course, desirable to retain a sumcient amount of moisture inthe finished paper to render it pliable and thereby to avoid breakagewhen folded as would be the case if the finished paper should becomeexcessively dry and the main'object of the present invention is toprovide simple and highly efficient means for automatically maintaininga relatively small but uniform moisture content in the paper as it isdelivered from the machine.

In other words, I have sought to establish a close regulation of thetemperature of the cylinders by automatically regulating the amount ofsteam admitted to the cylinders.

Another object is to provide ,means for automatically shutting oil thesteam supply to the cylinders in case the paper should break.

Other objects and uses will be brought out in the following description:

The drawing represents a side elevation of a paper making machine inwhich the drying cylinders and various portions of the apparatus forautomatically regulating the amount of steam passing to the cylindersare shown diagrammatically.

As illustrated, the drying cylinders A are rotatably mounted upon asuitable supporting frame B and are connected by branch pipes 1 to acommon distributor pipe or head 2 which, in turn, is connected throughthe mediumv of a valve 3 to a main supply pipe 4, the latter beingadapted to be connected to a source of steam supply, not shown, thebranch pipe 1 leading to the uppermost cylinder being partly brokenaway.

The distributor pipe or head 2 is connected by a relatively small pipe 5to a pressure regulator 6 of the diaphragm type having its diaphragmprovided with a bearing member 7 adapted to engage the underside of alever 8 having its fulcrum 9 relatively close to the bearing member 7,said fulcrum 9 being mounted upon the frame of the regulator 6 andengaged with the upper edge of the lever 8.

One arm of the lever 8 is relatively long as compared with the other armand extends horizontally a considerable distance from its fulcrum 9 anddiaphragm bearing 7 and is adapted to (Cl. 3H8) receive and support aweight 10 which is slidable along a scale 11 on the lever to partiallyoppose the steam pressure against the diaphragm tending to raise theweighted end of the lever.

That is, the pressure of; the steam passing from .0 the distributinghead to the regulator 6 tends to raise the diaphragm and to effect acorresponding elevation of the longer end of the lever 8 against theaction of the weight 10 for bringing into action suitable means,presently described, for moving the valve 3 toward its closed positionand thereby reducing the amount of steam passing to the cylinders A, itbeing understood that the period of closing the valve may be regulatedby simply adjusting the weight 10 along the scale 11 on the lever 8.

The valve 3 is normally open and preferably of theself-opening type andhas its stem 3' connected to a'sylphon or bellows 12 which, in turn, isconnected by a pipe 13 to a second sylphon or II bellows 14.

The stem 14' of the bellows 14 is engaged in a cam slot 15 of a rotarywheel or member 16, which, together with the regulator 6 is mounted upona supporting base 17 and is adapted to be driven by an electric motor 18indicated diagrammatically in the drawing.

This motor 18 is preferably of the reversin type and is controlled byany suitable reversing switch 19 having its movable member 20 pivoted at21 to the motor case on the base 17.

The switch member 20 is provided with an extension 22 which is connectedby a link 23 to the lever 8 for transmitting motion from said lever toone or the other of the contacts of the switch 19 and thereby. to causethe operation of the motor 18 and cam wheel 16 in one direction or theother.

For example, assuming that the lever 8 is in its normal position andthat the valve 3 is open and also that the tube 13 and bellows l2 andMore filled with liquid in which case the bellows 12 will be compressedto expel its liquid through the tube 13 into the bellows 14 fordistending the latter. I

Under these conditions, the weight 10 will have been adjusted to apredetermined position along the lever 8 to substantially counterbalancethe steam pressure in the diaphragm chamber 6 and thereby to hold theswitch member 20 in a neutral position between the opposed terminals ofthe switch, the graduations of the scale 11 serving to indicate thesteam pressure in pounds per square inch so that the weight 10 may beaccurately set to such position as will normally countel-balance thesteam pressure in the chamber 6.

It is now clear that if the steam pressure in said chamber should exceedthe predetermined degree at which the weight 10 is set, the adjacent endof the lever will be elevated to bring the switch member 20 incontactwith the lower terminal of the switch 19 for closing the circuitthrough the motor 18 for operating the same .to transmit its angularmotion to the cam wheel 16 in the direction indicated by arrow X.

This angular movement of the cam wheel 16 will cause its cam slot 15 tocompress the bellows 14 and thereby to expel its liquid through the pipe13 to the bellows 12 for distending the latter to move the valve 3toward its closed position, the efiect of which is to reduce the supplyof steam to the cylinders A.

As previously intimated, it is desirable to maintain a relatively lowbut uniform moisture content in the paper as the latter passes aroundthe cylinders A and it is for this purpose that the weight 10 is set toa predetermined position along the scale 11 to normally counterbalance apredetermined steam pressure in the diaphragm chamber 6 and cylinders Awhich will be most eflicient for maintaining the desired moisturecontent, it being understood that this moisture content is dependentupon the temperature of the cylinders and that thetemperature of thecylinders is dependent upon the. amount of steam admitted thereto.

For example, if the paper should become excessively dry by reason ofexcessive temperature of the cylinders, the supply of steam to saidcylinders should be reduced while on the other hand if the paper shouldbecome excessively moist due to the lower temperature of the cylinders,the supply of steam to said cylinders should be increased, and in orderto prevent these widely varying temperatures of the cylinders A andresultant widely varying moisture content of the paper, I have providedmeans controlled by the steam pressure in the cylinders for limitingthese variations within a very small margin determined by the setting ofthe weight 10 on the lever 8 which setting represents the' desiredmoisture content sought to be maintained in the paper.

With this understanding, it will be seen that if the temperature of thecylinders is above the predetermined degree resulting in reducing themoisture content of the paper below its predetermined amount, it followsthat the steam supply to the cylinders is proportionately excessive andthat the steam pressure in the diaphragm chamber 6 will be sufiicient toraise the lever 8 against the action of its counterweight 10 therebycausing the operation of the motor 18 and cam wheel 16 for forcing theliquid from the be1lows14 to the bellows 12 through the pipe 13 forpartially closing .the valve 3 and thereby reducing the amount of steampassing to the cylinders and instantly reducing the steam pressure inthe diaphragm chamber 6 to allow the weight 1 to return the lever 8toward its normal position, thus opening the switch member 20 andstopping the further operation of the motor 18 and cam wheel 16.

On the other hand, should the moisture content of the paper exceed thepredetermined amount, it

means that the temperature of the cylindersA is reduced below itspredetermined degree as indicated by the position of the weight 10 onthe lever 8.

Under these conditions, the steam pressure in the diaphragm chamber 6will, of course, be reduced, thereby allowing the weight 10 to depressthe adjacent end of the lever 8 and incidentally to cause the switchmember 20 to contact with the upper terminal of the switch 19 forreversing the operation of the motor 18 and cam wheel 16 driven thereby,thus distending the bellows 14 and allowing the valve 3 to open andthereby to compress the'bellows 12 for expelling the liquid therefromthrough the pipe 13 into the previously distended bellows 14.

This opening of the valve 3 allows free flow of the steam to thecylinders for increasing the temperature thereof and correspondinglyreducing the moisture content of the paper and at the same timeincreases the steam pressure in the diaphragm chamber 6 for restoringthe lever 8 and parts actuated thereby to their neutral positions thuscausing a partial compression of the bellows 14 and resultant partialclosing of the valve 3 to its neutral or substantially balancedposition.

It is now evident that any slight variation of the moisture content ofthe paper above or below the predetermined degree indicated by theposition of the weight 10 on the lever 8 will incidentally cause theoperation of the switch member 20 to its neutral position, therebyestablishing a very close regulation of the moisture content in thepaper by maintaining a more uniform steam pressure in the cylinders Aand in the diaphragm chamber 6 and thus maintaining a more uniformtemperature of said cylinders.

It is quite evident, however, that the lever 8 may be operatedindependently of the steam pressure in the diaphragm chamber 6 and thatsuch operation may be effected automatically by the varying tension ofthe paper in transit from one roll to another and for this latterpurpose I have shown a lever consisting of a rock shaft 24 having crankarms 25 and 26, the crank arm 25 being provided with a roller 27yieldingly held by its own weight or otherwise against the inner face ofthe paper between two of the rolls A where the paper is subject toslight sag when its moisture content exceeds a predetermined amount andis adapted to straighten when the moisture content is reduced below thatamount.

This alternate sagging and straightening of the paper under varyingdegrees of humidity is utilized for the operation of the crank arm 25and its rock shaft 24, the other crank arm 26 being connected to one endof a cable 28 which is passed over suitable sheaves 28 and has its otherend connected to the weighted end of the lever 8.

It is now evident that if the paper should sag by reason of excessmoisture therein, the crank arm 25- would follow the sagging movementthereby elevating the other crank arm 26 for slackening the cable 28 andallowing the weight 10 to depress the lever 8 for closing the switchmember 20 against the upper contact of the switch 19 with the resultantoperation of the motor 18 and cam wheel 16 for distending the bellows 14and allowing the valve 3 to open and thereby to compress the bellows 12for circulating the liquid in the tube 13 back into the previouslydistended bellows 14, the effect of which is to, increase the volume ofsteam flowing to the drying cylinders.

If desired, the downward movement of the weighted end of the lever maybe retarded by means of a dash pot 8 having its movable member attachedto said lever as shown.

On the other hand, as soon as the paper begins to straighten by reason01' its reduced moisture content resulting from the increasedtemperature clockwise direction thereby moving the crank arm 26downwardly for raising the weighted end of the lever 8 through themedium of the cable 28 thus bringing the switch member 20 into contactwith the lower terminals ofthe switch 19 for reversing the operation ofthe motor 18 and its cam wheel 16 to compress the bellows 14 and therebyto expel the liquid therefrom through the pipe 13 into the previouslyexpanded bellows 12 for partially closing the valve 3 and thus reducingthe volume of steam passing through the cylinders A.

If desired, the movement of the crank arm 26 may be utilized forindicating the amount of such movement from a predetermined positionrepresenting approximately the amount of moisture content which it isdesired to leave in the paper, and for this purpose the lever isprovided with a pointer 30 movable along a relatively fixed grad uateddial 31 representing percentages of moisture content of the paper orvarying temperatures of the cylinders A according to the election of theuser.

when the operation of the lever 8 is to be controlled by the tension ofthe paper a through the medium of the crank arm 25, suitable means isprovided for assuring the complete closing of the valve 3 in case thepaper should break, thereby cutting of! the supply of steam to theseveral cylinders.

For this latter purpose, a mercury switch 32 is mounted upon the crankarm 26 and is connected by wires 33 to a battery C and a solenoid 34having its plunger provided with an oifsetarm 35 which is adapted toengage a button 36 on the adjacent portion of the cable 28 when thesolenoid is energized.

This mercury switch 32 is arranged to open when the crank arm 26 is in asubstantially horizontal position and to close the circuit throughthesolenoid 34 when the crank arm is elevated from said normal positionthereby energizing the solenoid 34 for raising the weighted end of thelever 8 in the manner previously stated.

That is, in case the paper should break, the crank arm 25 wouldmovedownwardly under its own weight, thereby rocking'the shaft 24 and crankarm 26 in a counterclockwise direction for closing the mercury switch 32and thereby energizing the solenoid 34 to draw its plunger downwardlyfor operating the cable 28 and lever 8 connected thereto, thus causingthe closing of the valve 3 in the manner previously described.

This angular movement of the rock shaft 24 may also be utilized for theoperation of a three phase synchronous electric generator 37 having oneof its elements secured to the shaft or to the crank arm 26 co-axialwith the rock shaft for angular movement therewith and its other elementin fixed relation thereto and connected by wires 38 to a three phasesynchronous motor 39 having a cam member 40 secured to its shaft torotate therewith and adapted to bear against the underside of theweighted end of the lever 8.

The slip rings of the synchronous generator 3'7 and the field of themotor 39 may be connected to the same source or to different sources ofelectric energy, not shown, for supplying current thereto. Y

Under the construction last described, if the moisture content of thepaper exceeds a predetermined amount, it will sag as shown by full linesin the drawing thereby allowing the crank arm 25 to move downwardly byits own weight for rocking the rotary element ofthe generator 37 andthereby transmitting its current to the motor 39 for moving the cam 40away from the lever 8 to allow the latter to rock downwardly under itsown weight for closing the switch member 20 against the upper contact ofthe switch 19 to close the circuit through the motor 18 and thereby tocause the operation of the cam wheel 16 in a direction opposite to thatindicated by the arrow for distending the bellows 14 and allowing thevalve 3 to open for compressing the bellows l2 and instantly forcing theliquid therefrom through the pipe 13 into the previously distendingbellows 14.

This opening of the valve 3 will allow free flow of the steam to thecylinders A for raising the temperature of the same and thereby reducingthe moisture content of the paper.

Then, as the moisture content of the paper is reduced, the paper tendsto straighten thereby rocking the crank arm 25 upwardly and effecting acorresponding angular movement of the rotor of a generator 37 in theopposite direction for reversing the direction of rotation of the motor39 and its cam 40 for elevating the adjacent end of the lever 8 andthereby closingthe contact member 20 against the lower contact of theswitch 19 resulting in a reverse operation of the motor 18 and its camwheel 16 for compressing the bellows 14 and forcing the liquid therefromthrough the pipe 13 and into the bellows 12 for closing the valve 3 toreduce the steam supply to the cylinders and also to reduce the steampressure in the chamber 6, thus allowing the lever 8 and switch member20 to return to their neutral positions under the action of the weight10.

A stop shoulder 42 is mounted on the frame B in the path of movement ofthe crank arm 26 to limit the upward swinging movement of said crank armand also to limit the downward movement of the crank arm 25 inv case thepaper should break at which time the mercury switch 32 will have beenclosed for energizing the solenoid 34 to operate the cables 28 forraising the weighted end of the lever 8 and thereby causing the closingof the valve 3 in the manner described.

The generator 37 is preferably of the Selsyn remote control type forsynchronously operating the motor 39 while the diaphragm chamber 6,lever 8, switch 19, and motor 18 are similar to corresponding parts ofwhat is commonly known as the Brooke Constant Pressure Regulator shownin catalogue V-2 issued by the Brooke Engineering Co. Inc., 1321 ArchSt., Philadelphia, Penna, with the additions shown and described foradapting it to'the regulation of the moisture content of paper makingmachines.

It will be seen from the foregoing description and the accompanyingdrawing that this apparatus is particularly simple, practical andeflicient for automatically establishing and maintaining a predeterminedand substantially uniform moisture content in the paper and that thismoisture content may be varied at will by simply adjusting the weight 10to different selected positions connected to and controlling theoperation of said valve; of a lever engaged with and actuated in onedirection by the tensioning of the paper whentherein is transferred fromone to the other, a weighted lever, means brought into action by themovement of the lever under its own weight for operating one of thebellowses and thereby causing the operation of the other bellows formoving the valve in one direction, and means actuated by varying tensionof the paper for operating said lever against its weight for reversingthe operation of the bellowses and thereby to move the valve in areverse direction.

v WILLIAM J. OBRIEN.

